It seems that the Twitter Widget needs updating with the latest Twitter APIs for URL handling. All links which pass through Twitter are now wrapped inside a t.co url. Most Twitter clients, however, use the new APIs so that the original link is displayed in the client or on the Twitter website.
The Twitter Widget on WordPress hasn’t been updated so all links appearing in the feed now show as t.co urls giving no clue as to where the link will take the reader. This deters some people from clicking the links. Please could the Twitter Widget be updated to correctly handle t.co wrappers from Twitter and display the original url instead.